To meet the demands of an increasingly telephone-dependent public, the telecommunications industry continually develops advanced systems to enhance the efficiency and reliability of telecommunications service. As a result, it is quite common for customers to request new service features which may require transferring the customer's telephone line from one central office switch to another. Such a line transfer ordinarily implies a change in the customer's directory number since a particular range of directory numbers traditionally correspond to a particular central office switch. Each central office switch historically serves only one or more blocks of directory numbers, wherein each block has a unique office code. In the North American Numbering Plan, the 10 digit number is the area code ("NPA") followed by an office code (generally referred to as "NXX") followed by four other digits. For example, the office code for the directory number "708-555-2345" is "555". When a customer line associated with a given directory number is transferred from a first switch to a second switch, the customer's current office code is absent from the blocks of office codes conventionally served by the second switch. Normal practice in such a case would require a directory number change.
More than ever, society relies on telephone-related services to sustain businesses, meet civic responsibilities and maintain personal relationships. A telephone number (i.e. directory number) is no longer viewed as a disposable series of ten digits which are used for quick access to a particular individual. Indeed, some businesses use the power of directory number recognition to gain a competitive advantage (e.g. an extermination service which can be reached at directory number "708-555-BUGS").
Accordingly, many customers, especially business customers who have accrued good will using a particular directory number, want to avoid the inconveniences associated with a directory number change when changing central offices. To accommodate such customers, systems exist which properly route incoming calls to customers who have "non-traditional" directory numbers. A non-traditional directory number is a telephone number which retains an office code characteristic of a first central office switch while the customer line identified by the directory number is actually served by a second central office switch. One exemplary embodiment of such a system is a database which stores routing data for non-traditional directory numbers as disclosed in U.S. Pat. No. 5,237,604 to Deirdre Hoesl entitled "Arrangement for Serving a Telephone Office Code from Two Switching Systems" which issued on Aug. 17, 1993 (hereinafter, the Hoesl patent). The Hoesl patent describes a central database which may be accessed by a plurality of switches for routing data pertaining to non-traditional directory numbers.
An important reason for implementing the central database disclosed in the Hoesl patent is reflected by the dynamic nature of the local telecommunications industry. As the monopoly held by local exchange carriers becomes competitive, it is anticipated that the traditional relationship between a directory number and a central office switch, in which the directory number includes an office code corresponding to an office code of the central office switch by which it is served, will become obsolete. It is now common practice to rapidly recycle directory numbers when the number of new customer lines being added to the service base of a central office switch exceeds the number of available unused directory numbers. A recycled directory number is telephone number previously used to identify a customer line which has since been disconnected. Since there is now no guarantee that the directory numbers available for recycling will contain an office code which corresponds to an office code of the central office switch for which it is needed, recycled directory numbers are often non-traditional directory numbers. Further, local service competition will induce some customers to change from one LEC to another resulting in inter-carrier customer line transfers among switches and an even greater use of non-traditional directory numbers.
Maintenance of a central database which stores all routing data associated with non-traditional directory numbers in a local telecommunications network (i.e. a local number portability (LNP) database) is currently the responsibility of a single local exchange carrier. The LNP database is manually updated in response to circumstances such as when a customer who wants to retain a current directory number requests a service feature which is not available on the customer's current central office switch. The conventional LNP database update process requires a service order technician who receives the customer request requiring a switch transfer to notify an LNP database technician of the customer's directory number, current switch identification and new switch identification; this is currently communicated via facsimile. Upon receipt of the facsimile, the LNP technician manually enters the customer's directory number and corresponding routing data (which is based on the new central office switch identification) into an appropriate table in the central LNP database. The routing data allows incoming calls to the customer's directory number to be delivered to the central office switch which actually serves the directory number, even though the office code of the directory number actually identifies another central office switch. A similar LNP database update procedure also occurs when a new customer line, identified by a recycled non-traditional directory number, is added to the service base of a switch.
As described above, the current LNP database update procedure is labor-intensive, time-consuming and prone to error because of all of the manual actions required even for an individual telephone line transfer among the switches of a single LEC. The added administrative burden of manually coordinating routing data updates for directory numbers among central office switches for multiple LECs will result in even greater inefficiencies and error rates. Further, with multiple LECs using the LNP database, new concerns relating to fraudulent or unauthorized data changes in the LNP database must be addressed. Therefore, there is a need in the art for automatically keeping records, updating data changes and maintaining the integrity of a central LNP database such that incoming calls may be properly delivered to those customer lines which are identified by non-traditional directory numbers.